Yahoo Qmail Daemon and Mailman
My server’s mailman (or postfix) installation is mysteriously rejecting mail from one Yahoo! mail user. I don’t get it:
Hi. This is the qmail-send program at yahoo.com. I'm afraid I wasn't able to deliver your message to the following addresses. This is a permanent error; I've given up. Sorry it didn't work out. : 72.1.169.10 does not like recipient. Remote host said: 550 : Recipient address rejected: undeliverable address: unknown user: "[list name]" Giving up on 72.1.169.10.
72.1.169.10 is, in fact, the IP address of my server. [list name] is (in the real version) the real live name of the list. The list seems to work for everyone else. And it’s certainly not true that I, or my server, doesn’t like this recipient (or sender).
Aside from this anomalous behavior, it’s also funny that Yahoo! provides plain old unfiltered qmail bounce messages to its users. Wouldn’t you think a fully matured webmail service like Yahoo! would, by this point, have somewhat customized their mail error reporting messages? In fact, wouldn’t you think they would want to hide the fact that the use qmail at all, if only for security purposes? Couldn’t they hire an intern to write a few replacement error messages? Maybe I’m missing something.
A propos, I discovered this nice piece from McSweeney’s, entitled YAHOO’S MAILER-DAEMON AUTOMATED REPLY FOR FAILED E-MAIL DELIVERY IS GETTING A LITTLE TOO INTIMATE.
Update 5/30/06: Figured it out. Oddly, Yahoo! was looking up the CNAME DNS record for the domain name and replacing that in the mail header. While the original email went to e.g., listname@lists.mydomain.com, the message as delivered was addressed to listname@servername.mydomain.com. Because only lists.mydomain.com processed email for lists, the message bounced. The solution was to change lists.mydomain.com from being a CNAME entry to its own A entry with the IP address specified directly. That fixed the problem. I’ve never seen any other mail service work this way — gmail certainly doesn’t.
anon Jan 28
I found out a while ago that if you use “” in the To: .. yahoo kind of barfs. I had a filed a bug some time ago, and when i would respond it would do sometihng like ” Bob Soandso”. When the mail was sent it would silently fail. It may or may not be related.
Sven Hartge Jan 28
The funny thing is: Yahoo (or more its qmail) is correct here (sendmail replaces CNAMEs as well), you can interprete the RfC in such a way.
This is why I never use CNAMEs in anything related to mail, it is just bound to break.
Torrin Jan 28
You might want to put an ‘l’ at the end of that link. As in . . .
http://www.mcsweeneys.net/2005/4/12wayne.html
Adam Rosi-Kessel Jan 28
Sven: thanks for the pointer, I had no idea. Torrin, thanks for the correction, it’s fixed now.
jerome Jan 28
“In fact, wouldn’t you think they would want to hide the fact that the use qmail at all, if only for security purposes?”
Qmail is known for it’s security and everyone knows yahoo uses qmail anyway. It may even deter attacks to have that information so visible.
Gigi Marks Mar 16
I’ll admit up front–I am a dummy. But what does this mean when an email is returned? Does it mean the receipent’s firewall sent the email back?
Hi. This is the qmail-send program at yahoo.com.
I’m afraid I wasn’t able to deliver your message to the following addresses. (removed)
This is a permanent error; I’ve given up. Sorry it didn’t work out.
Sorry, I wasn’t able to establish an SMTP connection. I’m not going to try again; this message has been in the queue too long.
sherryshirley@hotmail.com Aug 29
i cannot send pic
Mike Dec 1
I’ve just recently starting having this problem also. It only seems to happen when I send emails to a certain person. I send a lot though, so could this have anything to do with it?
Is there any way to fix this or get around it?